posted
Is it okay to use fused distribution blocks for your -ground wires? I want to use the same distribution block for my +power wires as well so that I will have matching fuse blocks.
------------------ Soon to be shocking all of Ohio: 4 Shocker 12's sealed & 2 Power 800a2's www.sounddomain.com/2592
posted
The only problem I see is that the extra fuses in the electrical path could potentially be a current limiter, hurting performance. It can be done no problem, but use fuses wayyy larger than you need, or buy a length of metal rod and cut fuse-sized lengths as buss bars. Solder the rods in for no voltage loss through the connection. It should only make a difference if you are drawing a lot of current.
Agreed- Using fuses blocks to enhance symetricallity is nice, however, the cross-sectional are of even 60 amp fuses is moderately small compared to 4 gauge wire, meaning that the fuse will have a good deal of resistance (comparitively). Because the negative side is where the electrons come from, I don't see the advantage of sticking a fuse on that side...
But hey, if it looks good and it works, go for it.
Sam- Bussbars ? :-)
ShadowStar
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Posts: 2578 | From: Somewhere In the Northeast | Registered: May 1999
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A buss bar is basically the same as an interconnect wire, just made out of solid, inflexible metal. Those metal pieces used to join multiple capacitors are buss bars. So are those bars IN distribution blocks. If you still want the identical symmetrical look, do that, buy a segment of metal rod the same diameter as the fuses, cut to the fuse length, roughen the sides of the rod with something, roughen the fuse clips on the dist block, and solder in the rods. That way you'll never have a problem with voltage loss. Either that or buy a non-fused dist block from the same manufacturer in the same style, it should be available, and look relatively similar.
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I am currently using 4 four gang fuse blocks to power my 8 amplifiers. I use 2 fuse blocks for the positive wires, and 2 fuse blocks for the ground wires. The ground wires run (in backwards order) from the ampflifiers - through the fuse blocks - "t"ed to the bank of capacitors negative terminal - to the body of the vehicle - to the vehicle frame. I did this for two reasons, I wanted a symetrical look, and 2 for ease of repair if the system went down during competition. Even though I have not had to perform a emergency repair so far, the idea was to carry a few small (solid brass) rods, the same physical size as the fuses, in my pocket. If I was to have a fuse blow during competition, I could easily pull a fuse from the ground block and install one of the small rods in its place. Since the fuse blocks are close to each other, I could use the fuse to replace whichever "hot" fuse had blown and be back into competition within a few seconds. Like I said, I have not had to do this as of yet, but the piece of mind plays a big part in knowing you are ready for the worst in the event that something goes wrong. I have seen people at competitions that would blow a fuse and not be able to find one in time to stay in competition, and would loose by default. I had considered just carrying some extra fuses with me, but found it to be wiser to have the fuses in the vehicle at all times and to only carry the rods as a safety factor (ie. the rods won't crush in your pockets). I was also able to help out a friend of mine during a competition once. He had blown a fuse at a competition, and the dealer who was promoting the event was sold out of the size fuse that he needed. Since I was able to use one of the rods in place of a fuse, I was able to let him use one of my fuses to get his system ready for the next round. My suggestion would be to go for the fuse blocks for the ground side of the amps and everything should work out fine. As far as what would happen if a "ground" fuse was to blow, nothing different than if a "positive" fuse was to blow. either fuse will discconect the amplifier from the circuit which will cause that amplifier to repel from amplifying. I hope this rambling has helped you in your system design and fabrication. Good Luck
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HAHAHAHAAAA that David Navone guy is a fool. His one valid point was what I addressed, the voltage loss going through the fuse. Use a buss bar, and that's insignifigant. Pegasus, you need to be careful with your approach of replacing the main fuses in emergency with a solid rod. If the fuse blew, you need to use a multimeter and check if the wire shorted, or else if you put in the rod, you'll nullify the protection the fuse was supposed to provide, and possible ignite your car. I'm not accusing you of anything, just wanted to point that out for safety's sake.
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I understand where you are coming from, but remember one thing, If I was to replace the ground fuse with a solid brass rod, the positive fuse would still protect the system. If, after replacing the ground fuse, the positive fuse was to blow, then I would have a serious problem that would need immediate attention. Good Luck.
Hey.. Some people LIKE to think that they are correct :-D Especially if they are respected for anything, your opinion becomes fact and other peoples facts become opinion... Now if only I could get some respect ;-)
ShadowStar
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Posts: 2578 | From: Somewhere In the Northeast | Registered: May 1999
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posted
Geeeez. While I don't get the time to enjoy reading the advanced section that often, I'm glad I took a few hours to do so today. I read through the discussions on both lo- and hi-end wiring, both here and on the Carsound page, as well as this discussion on fusing grounds. It seems like I'm always on here agreeing with Dukk, even though we've never been introduced, and I have to AGAIN! Six years ago the thought came to me to fuse the grounds so that they matched the hot leads, and I tried it, using double the hot fuse rating to start, and eventually working up to triple on my bigger amps, just to be sure my grounds had a good connection. It worked fine. I never had a single problem. I've done it in a number of my other systems, and still not had any problems. Besides, I always knew that if my ground fuse blew, I should run away FAST. I do have to argue one thing with Dukk, though. When RF first released the 400x4s, I got a pair to play with. In the initial stage of the install, the ground to the chassis got bound up by the amp rack, and managed to pull the cable loose from the grounding strap(this is why I don't use crimpable 4g terminals anymore; only compression or centerpin). This in turn caused the amplifier to attempt to draw a ground through the RCAs, which fried the entire crossover network in the amps, as well as my RCA in/outs. Granted, we've tried this on newer RF amps, and they go into protect mode(mostly), as do most other amps by varying other companies, but there's those every once in a while happenings that bite you on the ass. Anyway, just happy to be a part of the forum from time to time.
------------------ -j "I can't control my shakes, how the hell did I get here ? Something about this so very wrong. I have to laugh out loud, I wish I didn't like this. Is it a dream or a memory ?" Sound familiar ?
Posts: 147 | From: somewhere over the rainbow | Registered: Aug 1999
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Oh yeah. That's the worst part of it. I've met and talked with both Dave Navone and Richard Clark on several different occasions. Hell, first thing Dave did was ask if he could take a picture of me, because of my multicolored beard, and he was extremely informative and friendly. He and Richard both are very nice, and once they realize you know what you're talking about, conversation can reach a higher level. BUT, I always got that vibe-"hey, here's some weirdo who knows enough to be dangerous, let's agree with him until he goes away and leaves us alone." They both do know a great deal, but I think that they believe their own press just a little too much. And for the record, Shadowstar, I DO think that some cable sounds better than others, but it's all in the individual application. The cable companies hype it too much, though. Sure, $15k stereo speaker cables DO sound better than zip cord. But how far down that road do you want to go ? $15k for speaker, $8k for RCA, and $2k for power. Great. I've just spent 25 grand on four cables. I think it's gotten a bit excessive, but I forget myself. I'm not allowed to use that word any more. My friends won't let me. Something about self-description...
------------------ -j "I can't control my shakes, how the hell did I get here ? Something about this so very wrong. I have to laugh out loud, I wish I didn't like this. Is it a dream or a memory ?" Sound familiar ?
Posts: 147 | From: somewhere over the rainbow | Registered: Aug 1999
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Well the point I was about to make was just made. If you blow the ground fuse before the hot (for whatever reason) the amps will inevitably pull + on the RCA shields to some degree or other. Now in most cases nowadays this current flow will be negligable but in a few your eq/xover/preamp or whatever upstream might not be very happy anymore. Lots of the RF amps blow these 1 amps diodes in the preamp section when this happens. I've replaced dozens. Other amps have a 50 to 200 ohm resistor that gives some reference to the secondary side of the power supply that could potentially smoke if you loose ground and keep hot. I personally am not a fan of ground fusing but using the solid buss's to do the matching ground connections.
Posts: 926 | From: Sugarland, Tx | Registered: May 1999
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posted
This is in response to the observation that the cross sectional area of a fuse is nothing compared to a 4 ga wire.
Let add my opinon to the tussle.
If that teeny weeny cross section area of the fuse stretched from the battery all the way to the back, then Ill agree it makes a difference. But fothe length of the fuse, it is designed to carry the amperage u require at no appreciable voltage drop.
Put in another way, if ur amps were beside the battery or the battery beside the amps, you wouldnt need such a big wire. The farther u r from the power source, the bigger the wire u need over that length of run.
Having a fuse less than inch long does not compromise that current carrying capability.
------------------ If u find urself in a hole, stop digging!
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Actually, a fuse in the way of a high current signal will hurt the power conducting capacity. Think of a garden hose. If you bend it and decrease the amount of space available for water to pass through, it will hurt flow no matter how much hose is left downstream or upstream from it. The fuse acts as a limiter to how much current can be flowed. That's the same reason in high voltage power wires, even the shortest connections are made with large gauge wire.
posted
Not to get on anyones bad side here, but according to SAM, the fuse is limiting my current capabilities. Should I remove all of my fuses (positive and/or negative) so that ALL of the current can reach my amplifiers? If the fuse is limiting the current on the negative side, then doesn;t it do the same thing on the positive side? Why would I, or why does everyone, use fuses if it is going to limit the current capabilities, wouldn't it be better to remove all fuses and let the amplifiers get the "full capabilities" of the current from the battery/alternator? Just looking to better understand what he means by the fuses limiting the current capabilities. Good Luck and God Bless.
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The point is that you WANT to limit the current at some point! If your amp draws 30 amps you might want to discourage it from drawing much more in case of a malfunction...
My point is that a 60 amp fuse will not 'limit' current until that 60 amps is exceeded..
------------------ Blow your mind - PORT your box!
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DUKK, I know that. I just wanted to find out why SAM LIN was saying that you do not want to fuse the ground wire due to it current limitations. Good Luck and God Bless.
The electrons which power the amplifier come from the negative side, right? The + side completes the circuit, and protects the amp from too great a potential draw due to shorting of the wire.
If the electrons come from the - side, then throwing a fuse, which has small section that is inherently higher resistance, puts resistive losses in a place where they logically don't need to be. The fuse obviously dissipates some power as heat simply because if >60 amps makes it break eventually then ~60 or slightly less must heat the metal up just a little...
Again- It won't screw UP your system. If you want to do it for cosmetics, why not?
ShadowStar
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HEY! I'm looking for a CHEAP used Clarion Thunderdome.. Hook me up!
Posts: 2578 | From: Somewhere In the Northeast | Registered: May 1999
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posted
The fuse is a limit on current, that's why it's used on the + wire. When current gets too high, it limits it. It's there for safety reasons, to completely cut off current if a wire shorts. If we didn't have to worry about setting our cars on fire, then yes, to get the most out of your amps all fuses should be removed and replaced with buss bars. As you get nearer to the fuse's rating, it's resistance increases. As ShadowStar said, the fuse is there merely for safety reasons, so putting another in there adds resistance. Power that could be flowing to the amps is getting wasted as heat trying to get through the fuse. Jell-O, there are large cross section fuses, the high amp ANL fuses. There must be a limit to fuse cross section if they are to serve their purpose, which is to melt before something else does.
Sam
[This message has been edited by Sam Lin (edited 05-24-2000).]
